The present invention generally relates to environmental control systems and, more particularly, to apparatus and methods of recuperating energy in environmental control systems.
Environmental control systems (ECSs) can be designed with a two-wheel air cycle machine (ACM), together with a primary heat exchanger, air compressors, motors to drive the air compressors, a condenser, a water extractor, a reheater, and a recirculating heat exchanger. A prior ECS design is shown in FIG. 1.
An ECS design has to address issues of cost, weight, and complexity. It needs to do so in differing operating contexts. For example, in aircraft, an ECS may need to operate differently on the ground versus in flight in order to achieve operating efficiencies. Efficiencies can potentially be achieved by introducing the energy recuperation of the ECS. They can also be potentially achieved by reduction of system weight, component size, and number of components.
As can be seen, there is a need for improved apparatus and methods to condition air for changing environments.